Flying-machine.



G. VORNDBAN. FLYING MACHINE.'

APPLICATION FILED MAYSI, 1913.

Patented Apr. 13, 11915.

SHEETS-SHEET 1l i@ a f THE NoRR/s PETERS Ca, PHOTG-LITHCL, WASHINGYON,n4 C G. VORNIDRADJ.

FLYING MACHINE.

APPLICATION men mAvsl, 1913.

Patented Apr. 13, 1915.

FLYNGr-IVIACHINE.

manana.

Application filed May 31, 1913.

T0 all whom it may concern:

Be it known that lf, Girone VORNDRAN, a subject of the German Emperor,residing at No. 126 Kanonenweg, Stuttgart, Germany, have invented acertain new and useful Flying-Machine, of which the following is aspecification.

lt has already been proposed to construct flying machines with flappingwings similar to those of birds or insects, but such ma chines have notyet given any remarkable 'results llhe reason for this is mainly duepoint of support against which this force can act. Generally, however,the air does not afford any such point of support because it is tooeasily displaced. The air presents a considerable resistance only whenit is suddenly displaced, that is to say, with a rapidly increasedvelocity and in such a case it presents actually a tremendously greatresistance and thereupon the secret of the flight of birds and insectsis based. By the fiapping wings known hitherto, for instance, by suchwings which open or spread out in their downward movement and foldtogether in their upward movement, an appreciable and suicientresistance of the air cannot be produced, because in every periodicalto-and-fro movement the velocity is m'l at the beginning and increasesgradually to the middle position of the stroke and then decreases tom'l. rllherefore the air will gradually begin to move at the beginningof the downward stroke and will offer a resistance to the movement ofthe wing, but this resistance is not sufficiently great and does notcorrespond in efficiency to the expense of energy because thedisplacement does not occur suddenly. A great part of the work expendedwould be used for the movement of the air and only a small part of thework would be used for lifting the flying machine. The constructionshould be such that at the beginning of the downward stroke of theSpecification of Letters atent.

Patented Apr.. i3, igil.

Serial No. 771,056.

wings the air is not displaced at all or very little and so that it doesnot acquire any velocity in the downward direction until the wing hasreached the middle point of the stroke and only then the wing shouldtend to displace suddenly the still air with a greater velocity whichwould then of course offer a very great resistance. rlhe fiight of birdsand insects takes place in the manner set forth above.

rlhe present invention has now for its object a mechanism for a flyingmachine with iiapping wings based upon the above described principles.

Figure l shows a plan view of the wing in the main positions, uppermost,middle, lowest. Fig. 2 is a front elevation showing said threepositions. Fig. 3 is a crosssection on line tv-B of Fig. l in a positionof the downward movement. Fig. 4: is a crosssection in a position of theupward move ment. Fig. 5 shows a plan View of another form of wing indifferent positions. Fig. 6 is a section on line A-B of Fig. 5 in aposition of the downward movement. Fig. 7 is a similar section in aposition of the upward movement. Fig. 8 a similar sectionv on line C-Dof Fig. 5 in a position of the downward movement. Fig. 9 is a section ina position of the upward movement.

The wing consists in a. known manner of a series of flexible ribs c, Y),which are covered with a suitable fabric. The ribs are movablerelatively to each other in the usual manner in the plane of the wing,so that they can be moved toward and away from one another. By means ofa suitable device, namely, a lever c or the like, an oscillatingmovement is imparted to the wing. By means of rods or similar devices d,each rnovably connected to the ribs, a, o and to a fixed point in theplane of the mean position of the wing, the ribs a, Z) are movedalternately toward and away from each other in such a manner that thefabric between the ribs is alternately slackened and stretched. Thecoperation of these two movements, namely, the oscillation of the wingsand the moving of the ribs toward and away from each other, is soregulated that the fabric is stretched in the upper and lower endposition of the stroke, while in the middle position of the wing thefabric is slackened and forms pocket-like recesses.

The section shown in Fig. 3 illustrates the manner in which the air isdisplaced by the wing during the downward movement or stroke. In thefirst halfv of the downward stroke, air represented by the horizontaldash lines is displaced, and the air represented by the dotted lines isdisplaced during the second half. At the moment the ribs pass the middlepoint of the downward stroke the air will have been displaced downwardonly to a slight extent s0 that the air has only attained a low meanvelocity. From the middle of the downward stroke the ribs are movingaway from each other so that the fabric of the wing again is stretchedand the displaced air is compelled to rapidly assume the velocity of theribs and may even exceed same. A great'resistance of the air occurs dueto the rapid increase of the velocity of the air displacement, which,similar to a solid body olfers a good support to the flying machine tobe lifted.

The upward movement of the wings is effected without expenditure offorce by the pressure of the air and thefall of the body as well asbythe elasticity of the ribs. The fabric of the ribs adapts itself tothe air pressure so. that no resistance occurs (see Fig. 4L). l

The motion of the wings does not require greatpower, because the airolfers only a small resistance in the first part of the downwardmovement and if the air offers a considerable resistance owing to therapid increase `of the velocity of the air displacement, then the wingor motor has attained considerable @is @sa prior to the excessive linaleffort.

ln the construction shown in Figs. 5 to 9 the wing consists of an arm aarranged nearly perpendicular to the longitudinal direction of theflying machine, and mounted on a ball or universal joint e so that saidarmV can swing in half a conical surface, as shown by the sections Figs.6 to 9. A second arm ZJ is arranged parallel to the longitudinaldirection of the flying machine in such a manner that it intersects thearm a; at the point c. rlhe triangle formed by a and Z) is covered withfabric. If the arm a is moved up and down through a more or lesssemiconical path as shown in Figs. G to 9, so that the wings are morespread out in its upper and lower end position than in the middleposition, then an action similar to that of the wing shown in Figs. l to4 is produced.

Having now described my invention what l claim as new and desire tosecure by Letters Patent is l. In a flying machine the combination withflapping wings having relatively movable arms and intermediate stretchedfabric, of `means for moving the arms relatively nearer to each otherduring the first half of the downward stroke and relatively farther fromeach other during the second half of the downward stroke.

Ina llying machine the combination with flapping wings having relativelymovable arms and intermediate stretched fabric, of means for moving thearms relatively nearer to each other during the first half of thedownward stroke and relatively farther from each other during the secondhalf of the downward stroke comprising two rods each movably connectedto said arms and to a fixed point in the plane of the mean position ofthe wing.

3. In a flying machine the combination with flapping wings havingrelatively movable arms and intermediate stretched fabric, of means formoving the arms relatively nearer each other during the first half ofthe downward stroke and relatively farther from each other during thesecond half of the downward stroke while one of the said arms is in astationary position relatively to the flying machine body.

In testimony whereof I aflix my signature in presence of two witnesses.

GEORG VORNDRAN. lVitnesses:

JOHANN OHMsTnDE, PAULINE MLLER.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner/ of Patents,

' Washington, ID. C.

